ENTOMOLOGICAL SOCIETY OF ONTARIO. 



The adult female gives birth to living young, differing m this resptcb from most 

 other scale insects. Ordinary, as with the Oyster-shell Bark-louse, eggs are laid beneath 

 the scale, which in the course of a longer or shorter time hatch and the young larvae 

 migrate to different parts of the plant ; but in the case of the San Jose icale young are 

 produced day and night for a period of nearly six weeks before the exhausted female 

 perishes, and this at the rate of about nine or ten every twenty-four hours;. 



After birth the young larva remains motionless for a short time beneath the scale 

 of the mother, it then forces its way out and runs over the plant, seeking a suitable 

 place to settle. It is a microscopic creature, pale orange in color with an oval body, 

 six legs and two feelers. The long, thread-like proboscis with which it sucks the sap 

 of the plant, is doubled on itself and lies in a groove of the body wall After crawling 

 about for a few hours, the larva settles down and works its bristle-like sucking tube 

 through the bark and remains fixed, if it be a female, for life ; and if a male, until 

 fully developed, when it will have a few hours more, during which it can fly about. 



The development of the scale begins even before the larva becomes fixed. The 

 secretion starts in the form of very minute, white, waxy filaments, which spring from all 

 parts of the body and rapidly become more numerous until within two days the 

 insect is entirely concealed by a whitish shell or scale, which now has a prominent 

 central nipple. The scale is formed by the matting and melting together of the waxy 

 filaments. As in the development of most insects, there are distinct periods of the larval 

 life, divided by moults of the skin, and in the case of the male scale insects marked by 

 important structural changes. The first moult takes place when the larva is twelve 

 days old. Up to this time the male and female scales are exactly similar in size, color 

 and shape, but after the moult the insects beneath the scales bear no resemblance to 

 each other. Themahs are rather laiger than the females and have large, purple eyes, 

 while the females have lost their eyes entirely. The legs and feelers have disappeared 

 in both sexes. Eighteen days after birth the second moult occurs and the males change 

 to the first pupal condition (pro-pur a) the small scales now assume an elongated shape, 

 the legs and feelers have re-apptared and there are now two prominent wing pads 

 extending along the sides of the bed y. About twenty days after birth the male insect 

 changes to the true pupa, in which all the parts shown in the pro-pupa are more 

 developed and a slender organ at the end of the body, called the style, has appeared. 

 From four to six days later, or from twenty four to twenty six days after birth, the 

 males mature and back out from the rear end of their scales. This is chiefly by night or 

 in the evening. 



The changes which have gone on beneath the female scales are less striking than 

 those described above. After the first rroult, the body of the female is practically an 

 almost circular flattened sac, with indistinct segmentation and without organs, except 

 the long sucking bristle with which it sucks up continuously the sap of the tree it is 

 infesting. The female moults a second time about twenty days after birth and the last 

 segment now shows the important characters of the mature female which are of so much 

 service in the exact identification of the species. The segmentation of the body at this 

 stage is quite distinct. 



Thirty days from birth the females are full grown and the embryonic young may be 

 seen within their bodies. The mature female, prior to the development of the young, is 

 1/30 of an inch wide and 1/25 of an inch long. 



The length of time necessary for the development of a generation varies somewhat, 

 and according to the Washington observations covers a period from thirty -three to forty 

 days from the time the young larva appears until it develops into a mature female, 

 bearing joung. The San Jo: 6 scale is enormously prolific. It has been calculated that 

 a single female may be the progenitor of 3,216 million descendants in a single season. 



A most serious Enemy. — It cannot be too often repeated that the San Jose scale is 

 one of the very worst enemies that the fruit grower has ever had to deal with. Its 

 inconspicuousness and presence upon trees in a dormant condition at the time when 

 the&e or scions from them are distributed, render it liable to be overlooked. Its great 



